Operating Manual Part 15

10-4 5300 ES Series Mobile Radio Operating Manual October 2008
Secure Communication (Encryption)
or digital encryption, and can also be used with the with the Motorola KVL-3000 Plus.
With this mode, keys are loaded into a SLN (Storage Location Number), typically from
0-4095. The Keys Table must then be programmed to link channel PIDs to a specific
SLN.
The use of this type of indirect linking allows keysets and key IDs to be changed
through OTAR while keeping the mapping from the channel or talk group the same. For
example, as shown in Figure 10.1, PID 4 selects SLN 24 which selects key slot 24 in
both keysets. This slot contains Key ID 69 in Keyset 1 and Key ID 91 in Keyset 2. Only
one keyset is active at a time. The actual key chosen between these two to transmit with
will depend on which keyset is active, Keyset 1 or Keyset2.
10.2.3 Maintaining Keys in Memory
The radio may need to be connected to a constant power source to preserve the encryption
keys in memory. The programming of the Infinite Key Retention parameter determines if
keys are permanently stored in memory or erased soon after power is removed.
When Infinite Key Retention is enabled, keys are stored in memory and are not lost when
power is removed. If it is disabled, they are removed almost immediately after power is
turned off.
With 5300 ES mobile models, the keys are maintained for approximately eight hours with
this feature disabled. However, a tamper switch causes immediate key erasure when the
radio cover over the logic board is removed.
10.2.4 Encryption Key Select
When multiple encryption keys are programmed (see preceding information), the KY SEL
option switch can be programmed to allow selection of another key for the current
channel. This feature changes the PID (hardware location) of the key of the channel for
analog or Talk Group for Conventional Digital and P25 Trunking, and the change is
permanent (cycling power or selecting a different channel does not reselect the original
key). Therefore, to switch back to the original key, it must be manually reselected. Proceed
as follows to select a key:
Note This feature is available on conventional channels only.
1 Press the KY SEL option switch and HWKEY x is displayed. The “x” indicates the
current key PID selection.
2 Rotate the Select switch to display the desired key and then press the Select switch to
select it. Press the KY SEL option switch again to return the display to normal
operation.